selftests/bpf: Use semicolon instead of comma in test_verifier.c

Just silence the following checkpatch warning:

WARNING: Possible comma where semicolon could be used

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Link: https://lore.kernel.org/r/1675319486-27744-3-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>